You could probably get a lot of your potential work done solely in Lightroom with assistance with maybe Elements for less money than Photoshop. But you need to define the type of work you do, what tools you’ll require. An awful lot of tools in Photoshop are unnecessary for some, and absolutely mandatory for others.

Lightroom (LR) is built from the ground up for modern digital photographers who amass hundreds to thousands of images. Photoshop (PS) is designed for photography and graphics arts needs, thus is a huge application (and expensive) with many parts a photographer might never see. Working directly in PS also creates very large files and editing is pixel-based, meaning the changes you make in PS are permanently saved to file and cannot easily be undone or not at all (e.g. cropping - once it's done that's it, unless you create new files all the time). LR, on the other hand, only uses parametric editing, which means the original file is left untouched with the edits written to a text file, not unlike a recipe card. Edits can be revisited and revised at any point in the future including things like cropping, B&W conversion, lens corrections, plus all the processing, masking and adjustments you might make.

PS has Adobe Camera Raw (ACR) which does parametric editing like LR and it has Bridge for the "cataloguing" side of things, but, neither is as "complete" as the modules in LR are. PS, ACR and Bridge can be used (and still are used by some), but it is not as integrated a workflow as is LR whose workflow has been designed to specifically meet the needs of digital photography including:

Library Module for importing, cataloguing (keywording, metadata, etc.) and exporting images - a hugely helpful part of LR that doesn't exist at all in PS (but does to a lesser extent in Bridge and PS Elements)

Develop Module for processing images, with adjustments and fine tuning not available in Photoshop except through Adobe Camera Raw

various modules for presentation including Print (simply the best workflow with Templates), Web and Slideshow (including PDF production) plus, in LR4, Book module;

LR4 even has a Map module for geotagging images.

Plus LR is 1/2 the price of PS, However, LR does not:

have a decent healing/clone brush (only "spot removal which can do a lot, but not as well as PS healing/cloning);

merge photos to panoramas;

merge photos for HDR

Photoshop does all of these tasks in 8-bit and 16-bit; PS Elements will also do these tasks, but only in 8-bit. Alternatively, there are a host of plugins that can be used with LR to accomplish these tasks and many others.

In fact, many photographers accomplish 80% or more of their digital photography workflow in LR (I use it for about 95%). Some choose to go to plugins for sharpening, B&W and/or a host of special effects. Others go to PS for those things.

In my humble opinion the could or should read - do I need PS in addition to LR.

Due to the extraordinary digital asset management capabilities of LR - not to mention the amazing allround capabilities of the package - LR really ought the be the foundation upon which your digital workflow should be built.

Whether one requires PS depends, as already mentioned in this thread, on what one is doing with one's photography. I do a lot of panoramic stitching as well as HDR imaging. In fact I combine both. For this purpse I use PS both for cost and practicality so I don't go mad switching between multiple software packages.

LR4 is not far off, you can download the beta version now from adobe labs. This really should be the bedrock. As your photography evolves so will your needs. There are potentially hundreds of packages out there that may then fulfill your needs.

Why do I have this strange feeling that the OP is just another version of the above, i.e., intended to make you click on the OP's website. Maybe because it is first post? Or maybe because he/she knows rather well that a question like this in a photo forum is bound to generate pages of debate and thus further exposure?

Yes, kind of. Why not have Photoshop have all the layout tools of InDesign or Lightroom all the video features of Premiere?

Nothing is impossible. Would you be willing to wait a few years, and pay $2500 for Lightroom Pro (or Photoshop Supreme) that does all this stuff, has a minimum system requirement that 90% of us can’t run (or runs dog slow) and is very, very complex to operate?

Yes, kind of. Why not have Photoshop have all the layout tools of InDesign or Lightroom all the video features of Premiere?

Nothing is impossible. Would you be willing to wait a few years, and pay $2500 for Lightroom Pro (or Photoshop Supreme) that does all this stuff, has a minimum system requirement that 90% of us can’t run (or runs dog slow) and is very, very complex to operate?

Excellent points!

OTOH, there is this company call Adobe out there with enormous rooms filled with workstations manned by highly competent programmers. They are divided in half, with each half working on very different solutions to almost the exact same problem. That's nuts! Stockholders should not be told about that.

And all that I would require is a little drop down box at the top center of the screen. The dropdowns would be..."Photoshop" and "Lightroom." At all times I want 100% access back to directly editing the RAW camera files and to have those edits immediately reflected forward into the appropriate Photoshop-like image layer with basic import changes such as stitching properly applied. I promise to only use non-destructive edits in the Photoshop part.

Piece o' cake! A couple mega-manyears and 8*10^6 lines of bug-prone code and it's done! Guys like me are the reason I stopped doing programming.

edit...Hey! If we're makin' movies with our DSLR's, why NOT put Premiere in Photoshop? That's a damned good idea, seriously! Would sell like discounted D800's at the next Independant Producers Conference.

And all that I would require is a little drop down box at the top center of the screen. The dropdowns would be..."Photoshop" and "Lightroom." At all times I want 100% access back to directly editing the RAW camera files and to have those edits immediately reflected forward into the appropriate Photoshop-like image layer with basic import changes such as stitching properly applied. I promise to only use non-destructive edits in the Photoshop part.

But pretty interesting. On a big pano that would probably require stitching the image in RAW format. And the memory needed would probably be a number larger than the sum of all fundamental particles in the visible universe.

Guess I will just have to wait for Photoshop Supreme Edition, or maybe even Photoshop Transcendent Edition.